"When fall arrives, motorists expect gas prices to be cheaper than they were in the summer," AAA spokesperson Jeanette Casselano said in a statement. "That's just not the case this year."

AAA reports a national average retail price for regular unleaded gasoline of $2.54 per gallon, down a couple cents from last week, but 14 percent, or around 32 cents higher, than this date last year. After the Labor Day holiday in early September, gas prices usually go down because demand pressures wane. Hurricanes Harvey and Irma, however, upended seasonal norms because of their impact on refineries in the southern United States.

"Back-to-back hurricanes packed a punch to Gulf Coast refineries' gasoline production and inventory levels," Casselano said. "As they play catch-up, gas prices are going to be higher than we'd like to see."

The last few refineries knocked out by Harvey came back online in late September and that led to relief at the pump for some Gulf Coast states. Florida, which saw big spikes after Irma because it doesn't have any refineries of its own, saw gas prices drop 6 cents per gallon, though the state average is still above the national par.

Because of the concentration of refineries, the Great Lakes market is usually the most volatile. Supplies in the region had to adjust to demand strains elsewhere and AAA noted federal estimates show gasoline inventories there at the lowest in nearly two years. Indiana, Michigan and Ohio two weeks ago reported big drops in gas prices, but erased the declines for last week. By AAA's metric, those were the only three states in the region to post price increases.

For the West Coast, the most expensive market in the country, AAA said gasoline inventories were on the slow road to recovery and the price at the pump was more or less stable.

On the broader market, a September rally in crude oil prices meant more drilling in the United States and total crude oil production is about 1 million barrels per day higher than last year. Higher oil prices would usually mean higher gas prices, but AAA said demand is easing as the U.S. market recovers from Hurricanes Harvey and Irma.

"While the market continues to be volatile, post-hurricanes, AAA expects gas prices to slowly, but steadily drop by up to ten cents in the coming month," Casselano said.

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